This laboratory uses mutants in the yeast Saccharomyces cerevisiae, and in the bacterium, Escherichia coli, to study the biochemical genetics of glycolysis, and important pathway in most cells. The present application is mainly for the following projects. (i) To clarify gene enzyme relationships in yeast phosphofructokinase, an enzyme with non-identical subunits which, possibly, are catalytic and regulatory, respectively. (ii) To pursue a study of the newly recognized controlling metabolite, fructose-2, 6-P2, in yeast, with the particular aim of obtaining mutants lacking it, in order to probe its synthesis and function. And (iii), to investigate the biochemical genetics of fructose bisphosphatase, in order to help clarify the roles of three mechanisms known to govern its activity in yeast - inhibition by effectors, repression, and catabolite inactivation - as well as to study the same reaction in E. coli.